TeO2 anisotropic Bragg light deflector without midband degeneracy

Abstract

An advanced acousto-optic light deflector has been designed using the acoustic shear wave traveling slightly off the [110] axis in TeO2. The midband mode degeneracy reported by Warner et al., which decreases the diffracted light intensity, has been shifted off from the active frequency region. A linearly polarized wave can be used as the incident light instead of the elliptically polarized wave used in the conventional deflector designed by Warner et al. The deflector yields a larger number of resolvable spots due to the broadened bandwidth. Experimentally, with 6328-Å light, a 3-dB bandwidth of 50 MHz was observed with a diffraction efficiency of 80% and an electric power of 350 mW. The new deflector has a capacity of 500 resolvable spots with a random access time of 10 μsec.